1. Field of the Invention
The present invention relates to building systems and, more particularly, to a curtain wall panel system utilizing an integrated panel mounting assembly.
2. History of the Prior Art
The prior art is replete with curtain wall designs and assembly techniques adapted for particular applications. In the main, these systems include various extruded aluminum shapes and profiles which form horizontal mullions that are secured to vertical, structural mullions. The mullion systems provide not only a structural lattice but also means for mounting panels thereon. The types of panels which may be used with such a curtain wall system vary. Transparent panels made of single or multiple pane glass are common. Likewise, solid panels of various materials such as stone, steel, aluminum and the like, have found widespread acceptance. Such panels may be used either separately or in combination with other types of panels. However, various assembly features must be taken into consideration when modifying the various panel sizes, shapes, thicknesses, as well as the type of panel material being utilized.
A large number of prior patents illustrate the state of the curtain wall construction as it pertains to both mounting techniques for panels and drainage aspects of the mullion. This is partly because there are a large number of considerations in the construction and installation of a curtain wall. These considerations include the manner in which the generally hollow aluminum mullion drains and the manner in which such mullions are used for the mounting of panels thereto. For example, glazing pockets are generally provided as a part of the mullion. The glazing pockets facilitate the mounting of the panels in direct engagement with the horizontal extruded members. Glazing strips are then received therein to prevent water infiltration. It is obviously important to maximize the effectiveness of the sealing configuration in order to prevent water intrusion. Several prior patents illustrating such extruded aluminum mullion and the glazing gasket configurations thereof include U.S. Pat. Nos. 4,773,193; 4,644,717; 4,194,776 and 4,055,923. These and other patents comprise technology dealing with curtain wall systems of which the current applicant is the inventor. The use of glazing strips and various sealing configurations are therein addressed.
In many instances the glazing pocket itself forms one of the most critical aspects of the mullion profile. Various panel sizes and mounting techniques necessitate variations in glazing pocket size and shape. Such modifications necessitate an emphasis on material characteristics. The usefulness of aluminum is most widely recognized relative to fabrication and its ability to be extruded into complex shapes. The cost of an extrusion die is much less than the cost of roll forming equipment typically used to shape steel. For this reason, aluminum has generally been utilized over roll formed steel for complex mullion configurations for curtain wall systems. There are certain designs, however, which incorporate the advantages of roll formed steel in a configuration that facilitates a structural interengagement allowing the use of steel over aluminum. One such design is set forth as shown in co-pending patent application Ser. No. 07/430,795 assigned to the assignee of the present invention. In that application, the advantages of both aluminum and roll formed steel are amply described, set forth and shown. Likewise, a number of prior art references are described and many of those references pertain to curtain walls and panel assembly mounting techniques. That patent application (Ser. No. 07/430,795) is incorporated herein by reference.
In the aforesaid co-pending patent application Ser. No. 07/430,795, the mounting of transparent glass and solid stone panels is addressed. The mounting of the stone panels necessitates various structural and functional design considerations. The mounting of lighter weight conventional panels is a more prevalent consideration. Conventional panels for curtain wall assemblies generally include a pair of stainless steel sheets, or the like, between which is disposed a honeycombed filler. Generally, the honeycomb is made from lightweight aluminum and a suitable adhesive is utilized to create a bonded sandwich configuration. The mounting of these panels to the curtain wall then becomes another design consideration. The panels in each case must comprise an element of the curtain wall which is sealably mounted therein. Such a sealed mounting generally requires the utilization of glazing pockets for the adjacent receipt of panels such as glass. A number of prior art designs address this particular problem, and the following patents manifest a variety of design approaches in the mounting of such panels in a curtain wall system.
U.S. Pat. No. 4,680,902 issued to Stefnick is a 1987 patent teaching a unitized partition system. This reference teaches a partition wall system utilizing a series of rectangular panel assemblies, each having outer and inner walls and a stiffening medium such as a honeycomb filler disposed there between. The honeycomb is recessed from the side walls. A spline is provided for being received within the recessed channel to facilitate assembly. This is not an integral construction and the spline is not taught to be integrally formed with the honeycomb panel. The splines may also include lateral extensions, which extensions may mate with the channels of adjacent panel assemblies to join the assemblies together.
U.S. Pat. No. 4,611,447 issued to Kretchel is a 1986 patent teaching a curtain wall and windowframe construction. The panels of this windowframe construction system comprise inner and outer sheets between which is sandwiched a thermal insulating core adhesively bonded thereto. The outer sheet extends beyond the perimeter of the core to therein define a region adapted for receiving a structural member providing the means for securing the panel to the curtain wall mullion system. A structural flange is thus provided in a configuration adapted for being received within the region defined by the outer wall and the perimeter of the core whereby the flange may be secured to both the core and the structural mullion by suitable fastening means. The structural flange is of the type adapted to be installed during the curtain wall construction process into the region left vacant behind the outer sheet.
U.S. Pat. No. 4,387,542 issued to Wehr is a 1983 patent teaching an integrated window and wall system. In this patent a wall panel constructed with inner and outer sheets and a stiffening core therebetween is provided in a configuration adapted for mainly engaging an extruded aluminum member defining a glazing pocket therewithin. Appropriate sealing means and baffle members are provided with a drain and mullion system that permits sealing and structural interconnection with the panels and the glass.
U.S. Pat. No. 4,685,263 issued to Ting is a 1987 patent teaching an aluminum plate curtain wall structure. A plate connection system is taught therein whereby panels are secured to the plates which are themselves secured to the support mullion. The plates are designed to move relatively free in relation to the perimeter members for purposes of thermal expansion or contraction. This reference also shows an extrusion joint having a spline and back flanges that receive a vertical perimeter extrusion.
U.S. Pat. No. 3,367,077 issued to Johnson is a 1968 patent for an enclosure structure for buildings. This reference teaches the utilization of an extruded aluminum member adapted for engaging glass panes in parallel spaced relationship. The inner and outer elements of the assembly are clamped toward one another to apply pressure to the sealing means against the glass.
U.S. Pat. No. 4,310,995 issued to Hanna is a 1982 patent for panel assemblies and components of the type utilized in building construction. The use of a honeycombed filler sandwiched between two spaced wall structures is taught. The peripheral region is constructed with a channel therein. Serrations are to be used for the channel edge members for interengagement therebetween.
U.S. Pat. No. 4,614,069 issued to Tanikowa is a 1986 patent for a prefabricated curtain wall assembly. Various aluminum extrusion configurations and mounting assemblies are set forth and shown therein. Likewise, panel assemblies which are secured to the structural mullion are generally referred to.
U.S. Pat. No. 3,734,550 issued to Vance is a 1973 patent teaching a building construction assembly. This reference teaches various extruded aluminum configurations adapted for engaging the panel members such as glass and sealed engagement therewith. Consistent therewith, a generally channel-shaped condensate gutter is taught with locking interconnection system.
U.S. Pat. No. 4,662,136 issued to Tonakawa is a 1987 patent teaching a prefabricated curtain wall assembly. Horizontal rows of prefabricated mullion units are mounted to the respective floor systems of the building. Again, a number of aluminum extrusion configurations and panel mounting systems are set forth and shown along with sealing means for use therewith.
The above described prior art of curtain wall systems manifests one design direction of the prior art in attempting to utilize the most economical and useful construction approach for panel assemblies. The particular application in the present invention includes a panel having an integrated structural interconnection region therein. This region is provided for securing the panel to the mullion and facilitating the presence of the glazing pocket therearound. Such an approach overcomes the problems of the prior art in panel mounting assemblies not incorporating an integral construction. In addition, the present invention provides a building system incorporating a method of facilitating direct panel mounting.